Mirage cleanup

[Paliak]

Fixes #6737.

Description of the problem being solved:

Cleans up handling of mirage skills. Applies various minor fixes.

Supersedes: #6753 Includes: #7238

Steps taken to verify a working solution:

• Test mirage skills handled in CalcMirage.lua

[Wires77]

I resolved conflicts for you, but double check that commit to make sure it looks as expected.

[Wires77]

This should probably stay so we don't break old trees unnecessarily.

[Paliak]

It wasn't removed. I just moved it into the preCalcFunc since that's the only place it's used.

PathOfBuilding/src/Modules/CalcMirages.lua

Lines 234 to 236 in ecd05e2

	local moreDamage = env.player.mainSkill.skillModList:Sum("BASE", env.player.mainSkill.skillCfg, "ChieftainMirageChieftainMoreDamage")
	-- Add new modifiers to new skill (which already has all the old skill's modifiers)
	newSkill.skillModList:NewMod("Damage", "MORE", moreDamage, "Tawhoa's Chosen", env.player.mainSkill.ModFlags, env.player.mainSkill.KeywordFlags)